Generally speaking, there are three technics for EVA foaming: the conventioanl flat foaming technique, the in-mold foaming technique and the injection technique. Hnarts , as top eva foam suppliers in China, will talk about the technics for EVA foaming today.

1. The Injection TechniqueThis technics will be the main trend, the product will be made just in one process, which is convenient and simple , but the same time, it requires the mold to be very precise. the principle is similar to that of the plastic industry, excpet that plastic industy requests immediate tooling and temperature of the tooling is different. Nowadays, tooling of some renowned sports shoes are using this efficient technique.

2. The Conventional flat Foaming TechniqueThis technique is quite popular for small factory, cost the machinery is comparatively low. Main process of thei technique is slicing, punching and grounding. Foaming conditions are relatively stable, temperature ranges from 160-170 degrees. The timing depends on the thickness of tooling, generally it takes 90-110 seconds /mm, pressure is 150kgs/m2.

3. The In-Mold Foaming TechniqueThis technique is mainly used for the secondary foaming of the sole of sports shoe. A general one can be made by putting the granulates into the tooling as per the prepared propotion of the material, but the difficulty lies in whether the tooling matches the formula., otherwise, hardness and multipying power cannot be controlled at the same time. The generally size is correct while the hardness is not enogh or verse visa. The foaming conditions are flexible depending on structure of the product, of course the main factor is time.

EVA foam is biodegradable, price is close to PVC but lighter, and odorless, it contains no heavy metal and no phthalate. plus it is trasparent, super low temperature resistant, water proof, and high heat sticking etc.